§ 227. 261 
THE CEPHALOPHORA. . 
Underneath the point of insertion of this vesicle upon the vagina, are 
various glandular appendages which open into this last or into the genital 
cloaca. But as yet their function is unknown. With the Pteropoda, and 
Heterobranchia, there is a single appendage only, consisting of a simple 
tube.) To this same category belongs, also, the dart-sac, — a very remark- 
able cylindrical organ opening into the genital cloaca." Its walls are 
quite thick, and on each side of its base is a group of more or less numer- 
ous caeca.“” At the bottom of this sac is a conical papilla which secretes 
2 calcareous concretion cf the form of a lance-head with the point down- 
wards, —the Dart. This is projected during copulation, and often remains 
sticking in the skin near the genital opening. Its loss is subsequently 
replaced by the secretion of another in the same place." 
The male copulatory organs consist of a more or less long, projecting 
Penis, which, when at rest, is either retracted freely between the other 
viscera of the cavity of the body, or enveloped wholly or in part in a proper 
sheath (Praeputium). 
This penis consists, nearly always, of a hollow fleshy cylinder, which is 
usually closed at its posterior extremity, and has, behind, a long flagelli- 
It is very long with Bulimus radiatus, Helix 
arbustorum, lactea, and vermiculata; very 
short, on the other hand, with Helix pomatia, 
nemoralis, and candidissima. It is entirely 
wanting with Helix fruticum, strigel/a, and 
rhodostoma. With Helix algira, it communi- 
cates directly with the seminal sac (see the figures 
of Erd!, and Paasch). With Doris, the Recepta- 
culum seminis has a peculiar structure; it is 
kidney-shaped, and from its concavity arises a 
very large excretory duct, arcuate, and opening 
into the genital cloaca, which has not only a 
caecal appendage, but also a short canal that 
communicates with the base of the uterus (H. 
‘Meckel, loc. cit. p. 496, Taf, XV. fig. 2). Further 
research must determine if the canal which Vord- 
mann (loc. cit. p. 60, Tab. III. fig. 5, d.) has 
observed upon the seminal sac of Tergipes with- 
out being able to trace it to its extremity, is a 
simple deverticulum, or a canal communicating 
with the female genital organs. 
15 An analogous appendix, of a round form, has 
been described with Cymbulia, and Limacina, as 
4 prostate by Van Beneden (Exerc. zoot. loc. cit. 
Pl. I. fig. 17, e. V. fig. 12, B.), and as a testicle by 
Eschricht, with Clio (loc. cit. Tab. III. fig. 25, 
26). There is a long glandular appendix upon the 
genital cloaca with Doridium, Pleurobranchaea, 
and Diphyllidia (H. Meckel, loc. cit. Taf. XV.). 
As yet the function of this gland is only hypotheti- 
cal. Perhaps it furnishes the viscid substance en- 
veloping the eggs during their deposition, or it may 
be a copulatory pouch (Bursa copulatrir). But it 
is quite probable that the penis enters the peduncle 
of the Receptaculum seminis during copulation, 
for with most Cephalophora the penis and the 
peduncle are of the same length. : 
16 The dart-sac, which is more or less long, is 
found with many species of Helix. It is absent 
with Helix algira, candidissima, cellaria, and 
verticilius. It is double with Hedi ericetorum, 
has so well figured. He found its contents to be 
spermatic particles, but, in regard to its being a 
seminal receptacle, he remarks: “This, however, 
cannot be considered wholly as its use; for it 
secretes a mucoid matter which may probably 
facilitate the passage of the ova through the vagina 
and cloaca,” p. 234, — Ep. 
and with Helix strigella, is replaced by two very 
long coeca; see Wohnlich, Erdl, and Paasch, 
loc. cit. 
17 Two considerable groups of dichotomously 
ramified caeca are found with Helix pomatia, 
adspersa, austriaca, lactea, naticoides, and ver- 
miculata, while with Heliz umbrosa, strigella, 
and striata, there are only four caeca on each side. 
With Helix incarnata, and nemoralis, there are 
three, and two only with Helix lapicida, arbus- 
torum, and personata; see Cuvier, Wohnlich, 
Erdl, Paasch, loc. cit. and Wagner, Icon. zoot. 
Tab. XXX. fig. 11,12. As to the use of these 
glandular tubes, I would suggest the view that 
they secrete a coagulable substance, which, during 
the coition, envelops the sperm like a spermato- 
phore to conduct it into the seminal sac. Indeed, 
I am much inclined to regard as the debris of a 
spermatophore the thin horny bodies of a peculiar 
aspect, which, with Helix hortensis, arbustorum, 
and nemoralis, often project out of the genital 
cloaca after fecundation, and which, when they 
have left it, are rolled in a spiral form at both ex- 
tremities. When carefully examined they will be 
found composed of several layers of coagulated 
albumen, and to be involved in the peduncle of the 
Receptaculum seminis ; see Huschke, in Meck- 
el’s Arch. 1826, p. 629, Taf. VII. fig. 9, and Carus, 
ra edi Arch. 1835, p. 495, Taf, XII. : fig. 
18 The dart is hollow and of the form of a cylin- 
drical stylet with Helix ericetorum, and striata ; 
but with Helix pomatia, hortensis, and adspersa, 
four, sharp denticulated edges, extending its whole 
length give it a very elegant form ; see Prevost, 
in Mém. de Genéve, loc. cit. V. p. 121, Pl. I. fig. 
7, aud Carus, in Miuller’s Arch. 1835, p. 494, Taf. 
XII. fig. 9, 12. 
It is probably an excitatory organ, for the snails 
reciprocally prick each other before coition.* 
* [§ 227, note 18.] For the relations of the dart- 
sac with the American Helices, see Leidy, loc. cit. 
He adds, “ The dart-sac and multifid vesicles, so 
common in European species, are very rare in 
American species.” The dart-sac has been found 
in only four species. — Ep. . 
